Advanced Queuing - Oracle

Dequeue Features
>
/* processes the next order available in the booked_order_queue */
CREATE OR REPLACE PROCEDURE process_next_order()
AS
dqqopt dbms_aq.dequeue_options_t;
msgprop dbms_aq.message_properties_t;
deq_msgid RAW(16);
book BOLADM.book_typ;
item BOLADM.orderitem_typ;
BOLADM.order_typ order;
BEGIN
>
dqqopt.dequeue_option := DBMS_AQ.FIRST_MESSAGE;
dbms_aq.dequeue('WS.WS_BOOKED_ORDERS_QUEUE', dqqopt, msgprop, order,
deq_msgid
);
>
/* for simplicity, assume order has a single item */
item = order.items(1);
book = the_orders.item;
>
/* assume search_inventory searches inventory for the book */
/* if we don't find the book in the warehouse, abort transaction */
IF (search_inventory(book) != TRUE)
rollback;
ELSE
process_order(order);
END IF;
>
END;
/
Visual Basic (OO4O): Example Code
Use the dbexecutesql interface from the database for this functionality.
Java (JDBC): Example Code
public static void setup_queue(Connection db_conn)
{
AQSession aq_sess;
AQQueue bookedorders_q;
AQQueueProperty q_prop;
try
{
8-78 Oracle9i Application Developer’s Guide - Advanced Queuing